Use of the percutaneous entry technique for medical procedures has expanded rapidly over the last few years. Originally, percutaneous entry was used for the introduction of small, flexible catheters for diagnostic radiographic studies. The use of percutaneous entry rapidly expanded to therapeutic devices such as balloon angioplasty devices, occlusion devices and now to endovascular stent graft delivery.
In the percutaneous entry technique, guide wires are used to guide the catheter through a needle puncture site, into the vessel and up to a target anatomy. Guide wires, in general, are simple devices that will control or influence the direction and advancement of the catheter as it is advanced through the vessel. The guide wires currently available to interventionists are, for the most part, designed to lead small flexible catheter devices through the vasculature. Large, stiff devices such as endovascular stent graft devices, are not controlled or influenced by typical guide wires when they are placed percutaneously. Very stiff guide wires are typically used with these types of devices; however, the stiff wires tend to be much stiffer than the vessels and will not traverse the vasculature easily. In addition, it frequently traumatizes the vessel walls.
In addition, the proximal ends of very stiff wires can damage or become lodged in the walls of the guide wire lumen of a delivery system.
The guide wires currently used for this type of procedure are multipurpose “heavy duty” guide wires. These guide wires do not have the characteristics to solve the problems of percutaneous deployment of large stiff devices.
The “double ended” guide wires available from Cook Inc., Bloomington Ind., are designed so that either end can be the distal end of the guide wire. One end may have a “J” curved distal end and the other end may be straight. This allows the physician the option to use either type distal end without using an additional guide wire. Again these guide wires do not have the characteristics to solve the problems of percutaneous deployment of large stiff devices.
The guide wire described in U.S. Pat. No. 6,254,550, to McNamara, et. al, does not possess the needed stiffness transitions nor the correct shape. The guide wire described in U.S. Pat. No. 6,001,068 to Uchino, et. al., does not have the combinations of flexibilities located in the curves so as to make the guide wire lock or anchor in place in the anatomy. In addition, this patent does not teach the use of a stiffness transition on the proximal end to protect the devices being used with the guide wire.
Throughout this specification the terms proximal and distal should be understood as being in the terms of a physician using the guide wire. Hence the term distal means that portion of the guide wire which in use is farthest from the physician and the term proximal means the portion of the guide wire which is nearest to the physician.